Pathology of the Urinary System II Flashcards
What causes Hypoxic/ Ischaemic injury?
Hypotension and/or ischaemia (heat stroke, dehydration)
* causes prolonged renal ischemia
* massive haemolysis- haemoglobinuric ATN
Necrosis of tubular epithelium and basement membrane
What is nephrotoxic injury?
- Nephrotoxins cause Direct damage to epithelial cells
- produces reactive metabolites in the tubular filtrates, which can cause renal tubular epithelial necrosis after reabsorption
- indirectly stimulate vasoconstriction of intertubular capillaries
- in absence of renal failure- reversible
What is AminoGlycoside toxiciy?
- Toxins are concentrated in lysosomes
- it escapes lysosomes to accumulate in the cytoplasm
- alters mitochondrial function and inhibits protein synthesis
- phospholipids accumulate intracellularly
What occurs when antifreeze/ oxalate nephrosis is absorbed?
- absorbed from the GIT
- A small percentage is oxidised by hepatic alcohol dehydrogenase to the toxic metabolites
- there is a direct interaction of the toxic metabolites on the tubular epithelium
- calcium-oxalate crystals precipitate in the tubular lumen, tubular epithelial cells and the interstitium
- tubular blockage -> degeneration and necrosis -> renal failure
What does oxalate nephrosis look like?
- large numbers of crystals in tubules
- usually arranged in rosettes or sheaves within the renal tubules
What is tubular ecstasia?
renal epithelial degeneration and necrosis with a preserved tubular basement membrane
What occurs when lilies are ingested?
- Vomiting and lethargy 1-5 days post ingestion
- The toxic ingredient is unknown
Occurs in cats
little amount = highly toxic
What occurs when grapes and raisins are ingested?
- Toxin is unknown
- Proximal tubular degeneration and necrosis
*
Name four toxins that cause haemoglobinaemia
- Chronic copper toxicity in sheep
- leptospirosis or babesiosis in cattle
- red maple toxicity in horses
- babesiosis or autoimmune haemolytic anaemia in dogs
What does haemoglinuric nephrosis look like grossly?
- renal cortex diffusely red-brown to blue-black
- Contains haemoglobin casts- red-black stippling of the capsular surface and continue into the cortex as radially orientated, dark red streaks
What is myoglobinuric nephrosis?
Acute and extensive muscle necrosis
* rhabdomylosis
* severe direct trauma to muscle
causes myoglobin release from the muscle
large concentrations of myoglobin in the glomerular filtrate can increase the tubular necrosis that occurs as a result of renal ischemia
What is leptospirosis?
- Interstitial nephritis
- causes abortion and stillbirths in livestock
- septicaemia, hepatitis, nephritis and meningitis
What does leptospirosis look like grossly?
- radiating pale streaks
- interstitial and subcapsular fibrosis
- jaundice
What does Encephalitozoon cuniculi look like?
- Occurs in rabbits
- obligate intracellular microsporidian parasite
- spreads through urine
- brain and kidney are the most heavily affected
- macrophages are unable to clear infection
What is ‘white-spotted kidney’?
- Common incidental lesion in young calves
- progresses to fibrosis when aged
Multifocal nonsuppurative interstitial
nephritis
What is pyelitis?
inflammation of the renal pelvis
What is pylenephritis?
Inflammation of the renal pelvis
* ascending infection
What is renal gout?
Deposition of urate crystals or urates
What species lacks the enzyme uricase?
humans, birds and reptiles
What is renal adenoma?
Rare, most common in horses and cattle
▪ Usually small and incidental findings
▪ Benign, arise from tubular epithelium
What is renal carcinoma?
- Most common primary renal tumours of dogs, cattle and horses
What is Nephroblastoma/Wilms’ tumour?
The most common renal neoplasm of pigs
and chickens
* Young animals(<2 y)
* Large masses, can be multiple
What animals are specifically prone to nephrotoxin ATN?
Foals
What is oxalate nephrosis?
The deposition of calcium oxalate crystals in kidney tubules
What species is leptospirosis most likely to cause intestinal nephritis in?
Dogs
What are the clinical signs of Encephalitozoon cuniculi?
- Weight loss, failure to thrive, neurological
What is the most common cause of white-spotted kidney?
- E.Coli
- Salmonella
- Brucella
What is Feline Infectious Peritonitis?
a Mutated Feline Enteric Coronavirus
What is Pyelitis?
Inflammation of the renal pelvis
What is vesicoureteral reflux?
Bacteria contaminated urine flows backwards from the bladder into the ureters
What is a renal adenoma?
Primary epithelial renal neoplasia
* usually a small and incidental finding
In what species is a renal carcinoma the most common in?
It is the most common primary renal tumour of dogs, cattle and horses
What is a nephroblastoma?
wilms tumor
Most common renal neoplasm of pigs and chickens
What two things cause acute necrosis?
- Toxic insult
- Ischaemia
What does ischaemia of the tubules result in?
Tubulorrhexis/ Tubulorrhectic necrosis
What usually causes pyelonephritis?
Vesicoureteral reflex
Bacteria contaminated urine
In what animal is the nephroblastoma over expressed?
Male GSD
What three things may predispose to a lower urinary tract infection?
- Catheterisation
- Uroliths
- Urine stagnation
What gender of dog is more likely to get a renal carcinoma?
Males over females
